Telephone system.



No- 826,534. PATBNTED JULY 2'4, 1906..

' U. G. 6: E. J. BURKE.

TELEPHONE SYSTEM.

APPLIOATIOK IILBD were, 1904 nnn'nwnn In 25, 1906.

UNITED STATES PEENT OFFICE.

CHARLES G. BURKE AND EDWARD J- BURKE. OF BROOKLYN, NEW YORK, ASSIGNORSOF ONE-HALF TO JOHN Q. A. WHITTEMORE, OF BOSTON,

MASSACHUSETTS.

TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented July 24, 1906.

Application filed August 6, 1904. Renewed May 25, 1906. Serial No.318.744.

To all whmn, it may concern:

Be it known that we, CHARLES G. BURKE and EDWARD J. BURKE, citizens ofthe United States, and residents of Brooklyn, county of Kings, and Stateof New York, have invented new and useful Improvements in TelephoneSystems, of which the following is a specification.

Our invention relates to telephone systems, and has, amon other urposes,the providing of a means w ereby irect batterycurrents may besuccessfully employed for thetransmission and reproduction of articulatespeech over all lengths of telephone-circuits.

The invention primarily consists in introducing into a telephone-circuita resistance additional to the ordinary variable resistance of themicrophone-transmitter, such additional resistance bein capable of beingvaried by variations of t e battery-current in the circuit of thetransmitter and to a degree corresponding with the extent of suchvariations.

The invention also consists in providing a battery and a device forproducing a counter electromotive force and so connecting them in atelephone-circuit as to improve the transmission.

The invention also consists in providin r a battery connected to a mainline and a device for producing a counter electromotive force.

connected in a shunt-circuit.

1 The invention also consists in providing a battery connected to a mainline and an electrolytic cell connected in a shunt-circuit.

The invention also consists in providing a battery, a transmitter, andan electrolytic cell connected in a circuit, a telephone connected in amain-line circuit, the said main line being connected to the saidcircuit on each side of the said electrolytic cell.

The invention consists in other features which appear in the followingdescription and in the drawing filed herewith and which form a parthereof.

Referring to the drawing,the figure illustrates our invention. I

1 represents transmitters connected to batteries 2. The batteries may beof any number of cells, their number depending upon the length andnature of the circuits.

The transmitters 1 and the batteries 2 are connected to devices 3 forproducing a counter electromotive force. The counter-electromotive-force devices may be of any form. We, however, preferably usean electrolytic cell. It consists of two terminals 4 and 5, immersed ina suitable electrolyte. The terminals may be-in the form of plates or inthe form of rods and may be formed of any material suitable for theirpurpose. In the preferred form of our invention the terminals 4 and 5 a1e formed of carbon. The terminals are inserted in an electrolytic fluid6, contained in a receptacle 7. The electrolytic fluid 6 may be water,acidulated or unacidulated, or any other fluid that will produce anelectromotive force counter to that producing or tending to produce anelectrolysis of the fluid. In the system illustrated ordinaryunacidulated water is used. Any number of cells may be used, and theymay be connected in series or in parallel.

The electrolytic cell operates as a variable resistance to produce avariable electromotive force according as the transmitter is varied inresistance by the sound produced by one speaking in the transmitter,which in turn varies the effective electromotive force produced at theterminals of the line. The variable resistance of the electrolytic cellproduced by varying current passing through the cell produces pulsationson the main line, which cooperate with and magnify the electricpulsations produced by the transmitter.

The main line 8 is also connected to the transmitter l and the battery 2and at the same time to the terminals 4 and 5 at each end of the line.The devices for producing counter electromotive force are thus connectedin shunt-circuits to the batteries and transinitters. Telehone-receivers 9 are preferably connecte in the main-line circuit 8.

1n the operation of thesystem the current The invention may be varied bythose skilled in the'art withont departing from the spirit thereof.

What we claim, and desire to secure byLetters Patent, is as follows:

1. In a telephone system the combination of a main line a battery, atransmitter, a device for producing a counter electromotor forceconnected in series with the said battery and the saidtransmitter and inparallel with the said main-line circuit.

2. In a telephone system the combination of ahmain line, a battery and atransmitter connected in series with the said main line, an electrolyticcell connected in a shunt-circuit to the said battery and transmitter.

3. In a telephone system the combination of a battery, a transmitter andan electrolytic ceases cell connected in series, a main line, a receiverconnected in the main line, the said main line being connected to thesaid circuit on each side of the electrolytic cell.

4. In a telephone system the combination of a battery a transmitter, adevice for producing a variable resistance connected in series with thesaid battery of the said transmitter, and in parallel with the mainline.

In testimony whereof we have signed our names to this specification inthe presence of two subscribing Witnesses.

CHARLES G. BURKE. EDWARD J. BURKE.

Witnesses:

EDWIN SEGER, GEO. W.-MILLs, Jr.

